The role of the Biostatistics Core in this Program Project is to support the clinical and laboratory-based projects. This includes collaboration with investigators in the design and conduct of research studies, statistical modeling, hypothesis formulation and data analyses. There are three major activities: (1) Consultation and collaboration in the planning, conduct, analysis and reporting of clinical trials in CML; (2) Consultation and collaboration with research investigators evaluating the cellular and molecular basis of response, to identify specific biological markers of CML accelerated phase or blast crisis, characterize patient response, and develop improved therapeutic modalities; and (3) Evaluation of the prognostic significance of these biological markers, based on their presence or quantitative levels over time in the patient.